Regenerative metallurgical furnace



L. B. LINDEMUTH 2,267,933 7 RBeEuERAwIvE METALLURGICAL FURNACE Filed Jan. 30, 1940 3 Sheets-Sheet 1 INVENTOR. LEW/s firfioA/l/lvozmurfi ATTORNEYS 1941. L. B. LINDEMUTH REGENERATIVE METALLURGICAL FURNACE ATTDRNEIQ Dec. 30, 1941. 1.. B. LINDEMUTH 2,267,933

REGENERATIVE METALLURGICAL FURNACE Filed Jan. 30, 1940 3 Sheets-Sheet 5 ATTORNEYS Patented Dec. 30,1941

UNITED STATES PATENT OFFICE REGENERATIVE METALLURGICAL FURNACE Lewis Byron Lindemuth, Port Washington, N. Y. Application January 30, 1940, Serial No. 316,291

2 Claims.

This invention pertains to regenerative metallurgical furnaces, such as open hearth steel furnaces, and more particularly to novel constructions and arrangements for cleaning the regenerative chambers thereof while the furnace is in operation and without hazard or discomfort to the workmen.

In my Patent 2,176,674, I have disclosed an improved construction for cleaning the regenerative chambers of such furnaces while in operation, the improvement consisting in the provision of a tunnel extending under the furnace from the regenerative chambers on the charging side to suitable entering manholes on the tapping side of the furnace. This arrangement permits of a tunnel of suflicient height, width and length to enable workmen, manipulating appropriate long-handled implements, to clean the entire base of regenerative chambers and without hazard or discomfort to themselves, during an interval that the chambers being cleaned are traversed by exhaust fumes from the furnace. Owing to the width of the tunnel, the workmen may stand some considerable distance away from the end of the regenerativechamber while cleaning it, and in, an atmosphere of cool, clean air drawn into the tunnel through the entering manholes andthence past the workmen and into the base of the regenerative chamber, owing to the draft or suction created at the furnace end of the chamber by the stack or artificial blowers while the chamber is being traversed by exhaust fumes.

.In certain furnace installations, however, special conditions preclude the provision of a cleaning tunnel of the dimensions above described permitting the manual cleaning aforesaid ofthe regenerative chambers during furnace operation. In some instances, the available space is-such that only a relatively narrow tunnel can be extended lengthwise of the furnace and adjacent the furnace ends of the regenerative chambers. Under these conditions, implements of su'mcient length to clean the chamber cannot be manipulated from the tunnel, and furthermore the workmen must operate for long periods so close to the regenerative chamber openings as to be subjected to uncomfortably high temperatures.

I propose in accordance with this invention to further improve upon the construction of my patent aforesaid and to eliminate the drawbacks of the narrow tunnel construction .where required; by providing the regenerative chambers with either motor-driven or manually operated the base thereof below the checkerwork and arranged upon actuation to convey directly into the cleaning tunnel, material, such as slag particles, cinders, dust, etc., accumulating at the bottom of the regenerative chambers.

According to my preferred construction, the

-base of the regenerative chambers is provided and geared or chain driven to the ends of the conveyor shaft. The conveyors extend from regenerative chambers into the cleaning tunnel through metal housings mounted in the partition walls, separating the regenerative chambers from the tunnel, these housings terminating in delivery funnels which are normally closed by metal caps or covers bolted or otherwise secured thereto. For assuring that theconveyor passages will be thoroughly cleaned, the bottoms of the passages are made of trough-like configuration by sloping the sides thereof from the side walls to a point just below the conveyor whereby the material accumulating in the base .will be fed to the conveyors by gravity. Accordingly and upon rotation of the conveyors, material accumulating in the passages ,is fed to the delivery funnels, from which it may be dumped into suitable receptacles, such as small track cars in the tunnel and thus conveyed away with verylittle exposure of the workmen.

As a further feature of the invention, I prefer to employ in conjunction with the construction aforesaid for cleaning the chamber passages, an arrangement of the brick checkerwork in the regenerative chambers, such that all matter, dust, etc., accumulating on the checkerwork,

may be easily deposited in the bottom of the mechanical conveyors permanently mounted in chamber topermit of its withdrawal into the cleaning tunnel. To this end, I assemble the brick in a series 'of vertical columns, each preferably containing in cross-section but a single brick, with thecolumns touching one another .only at'the corners, whereby a series ofsmoothwalled, vertical passagesare provided between columns. In consequence of this arrangement, dust and other debris will collect only on the tops of the columns, whence such accumulations may be forced into the passageways referred to by the action of compressed air jets or by other suitable implements introduced through port holes provided in the chamber walls above the checkerwork, the accumulations falling thence by gravity to the bottom of the chamber for removal.

In the drawings:

Fig. 1 is a sectional elevation at of Fig. 2 of an open hearth furnace embodying the invention, in accordance with the modification wherein the cleaning tunnel extends under the furnace to the tapping side.

Fig. 2 is a longitudinal sectional elevation through the furnace proper taken at 2-2 of Fig. 1.

Fig. 3 is a partial plan view of the furnace proper and an associated regenerative chamber, shown in partial section as taken along 3-3 of Fig. 1.

Fig. 4 is an enlarged axial sectional elevation through one of the conveyors and appurtenant assembly as taken at 4-4 of Fig. 3.

Fig. 5 is an end elevation 'of the tunnel endof one of the conveyors showing the terminal housing and motor drive assembly therefor.

Fig. 6 is an enlarged transverse sectional elevation through one of the conveyors taken at 6-3 of Fig. 4.

Fig. 7 is a partial sectional elevation similar to Fig. 1, and showing the invention as applied to a narrow passage tunnel construction.

, Referring to Figs. 1 to '6 inclusive, of the drawings. the furnace proper I has access at one end of the charging side thereof to regenerative chambers for air 2 and for gas 3 through the connecting fiues 4, 5 terminating inthe furnace in ports, such as 6. At the opposite end of the charging side thereof, the furnace has access to similar air and gas regenerative chambers 8, 9 through lines I 0, terminating in ports, such as I2. The regenerative chambers terminate at the ends remote from the furnace in fiues, such as I4, extending, in the usual manner, through reversing valves to sources of air and gas for one set of regenerators and to the stack for the other set, whereby air and gas are admitted to one set of regenerators and, after being heated up therein, pass into the furnace to burn there with an intense flame, the products of combustion passing out of the furnace through the other set of regenerators to the stack. The reversing valves, stack, etc., are not shown because they are of a known construction and form no part of the present invention.

The regenerative chambers are disposed in part nally of the regenerative chambers, thereby to provide unobstructed longitudinally extending passages 24 between the bottom of the checkerwork and the bottom of the regenerative .chamher in which the dust, slag, cinders, etc., accumulates.

aeemsa sages 24, the brick comprising ,the checkerwork are preferably assembled, as shown in Figs. 1 and 2, in substantially smooth-walled perpendicular columns 25, each having the cross-sectional dimensions of but a single brick, with adjacent columns overlapping slightly at the corners, thereby to provide separate smooth-walled vertical passages 26 extending from top to bottom of the checkerwork. In consequence of this construction, no appreciable amount of material can collect on the passageway walls of the checkerwork, such accumulations being restricted to the exposed upper surface 21 thereof.

In order to permit of removing, during furnace operation, material accumulating on these uppersurfaces 21, and to deposit the same in the passage 24 at the bottom of the regenerative chambers, the side walls 28 thereof are provided with a series of normally closed ports 29, through which suitable cleaning implements, such as a compressed air. line 30, may be thrustand manipulated by a workman, such as 3|. In this manner, all solid material suspended in the exhaust gases passing through the regenerative chambers and which is deposited therein, will ultimately be deposited in the passages 24 at the bottom of the chambers, in the manner indicated at 32, Figs. 4 and 6.

For removing such accumulations in accordance with the present invention, I provide the passages 24 with a series of mechanical conveyors, preferably screw-type or so-called worm conveyors, such as 33. As shown more in detail in Fig. 4, these worm conveyors are of the usual construction and comprise strips of sheet metal extending on edge helically about and welded to a supporting shaft 35. The conveyor may be made of a heat-resisting cast iron or other appropriate heat resisting metal capable of with- -standing the temperatures encountered in this portion of the regenerative chambers which ordinarily do not greatly exceed about 1200" F.

The conveyor shafts 35 extend the length of the regenerative chamber and project at the furnace end into the above mentioned cleaning tunnel, such as 36, described more in detail hereinafter. Each shaft 35 is provided with a series of worm conveyors 34, as shown in Fig. 4, these conveyors being slightly separated at their contiguous ends to provide space for bearings, such as 36, through which the shaft 38 is journaled. As shown in Fig. 6, bearings 36 are carried by supporting members 31 extending across the passages 24 and secured to the side walls 23 thereof. Also as shown in Fig. 6, the bottoms of passages 24 are provided with sloping sides 33, which slope downwardly from the side walls 23 to the center of the passage beneath the worm conveyors 33, to provide a trough-like base for depositing the accumulated material by action of gravity in the path of the conveyors. In consequence of this construction, rotation of the conveyors in the proper direction, will cause the accumulated material to be fed continuously from the stack end to the furnace end of passage 24, as indicated in Fig. 4 at 32.

At the furnace end of the regenerative chamber, each conveyor passes through a partition wall 39,- separating the chamber from the tun- I nel 36, and into a metal housing 40, of cast iron,

In order to prevent accumulation of dust, cinto sheet metal or the like, through which shaft II is journaled as shown at 4|. The housing terminates on its lower side in a delivery funnel 42, which is normally closed by a cover 43 bolted or otherwise removably secured thereto.

The projecting end 44 of shaft 35 may be provided with flat faces on its peripheral surfaces for manual actuation by a long-handled ratchet veyors is motor driven, as for example, by means of a small horse power electric motor 45, mounted on the housing 40 andlinked by means of a pedient to attempt to clean the chambers manually under such cramped conditions as the tunwrench. Preferably, however, each of the conchain drive 46 and cooperating sprockets ll, 48

to the conveyor shaft.

In the modification of Figs. 1 and 3, the furnace ends of the conveyors, closed by housings 40, extend into a cleaning tunnel 36, which latter extends from the regenerative chamber par- 7 tion walls 39 beneath the flues Q, 5 and III, II, and

beneath the furnace proper l,- substantially to the tapping side of the furnace as shown. The structure above the tunnel is supported on Ilibeams 49 forming part of the tunnel roof. The tunnel is disposed below the yard level It and is entered through manholes, such' as 50, normally closed by removable covers 5|. Also the tunnel is preferably of sufficient height to permit the workmen to stand erect, and extends somewhat below the bottoms-of the regenerative chamber passages 24 in order to permit of dumping the accumulated material from the conveyor delivery funnels 42, into a suitable receptacle, such as 52,

which may be small track cars.

Fig. 7 shows a construction wherein space requirements or other conditions do not permit of the wide tunnel 36 arrangement shown in Fig. 1, and wherein a narrow tunnel 53 must sumce, this tunnel extending along the length ofthe furnace and along the furnace ends of all of the regenerative chambers. Inbther respects. the construction is the same as in Figs. 1 and 3. Where the cleaning tunnel is restricted to such dimensions, as is sometimes the case. the imsages 2l, will be readily apparent. It is inexnel width does not readily permit of the insertion of sufficiently long cleaning [implements into the passages 24 for raking the accumulated material into the tunnel. Also in working so close to th chamber openings, the workmen are often exposed to uncomfortably high temperatures for relatively long periods. With the construction shown wherein the accumulations inpassages 2. are mechanically conveyed into the housing funnels 42 and dumped into waiting receptacles 62,

the workmen are enabled to remove the material portance of mechanical conveyors in accordance with the invention for cleaning the chamber pas very quickly and with little or no discomfort.

I claim:

1. A metallurgical furnace having a regenerative chamber, checkerwork providing smoothwalled vertical passages through said'chamber from a height below its ceiling to a height above its base, spaced checkerwork supporting walls in said bas providing unobstructed passages extending the. length of said chamber, screw-type conveyors of heat resisting metal in said passages arranged upon actuation to convey to a point outside said chamber, material accumulating in said passages, a housing. having a removable member, enclosing the terminus of each said conveyor and means for rotating said conveyors.

2. In a metallurgical furnace having a regenerative chamber, checkerwork in said chamber extending from a height below its ceiling'to a' 1' 

